1) She once knew him.
2) Had she seen him before ?
3) He has known her from a child (=since childhood).
4) Ask him whether he knows her.
5) He brought me acquainted with her.
6) She did not recognize them.
theory of knowledge of dialectical materialism
blanZhengweiwOZ卜U丫1 rens卜jlUn辩证唯物主义认识论(t heory ofkn。wle此eofd坛lectical mater认价皿)见认识论。